A salient advantage of wireless telecommunications is the wireless user may use his or her terminal anywhere. FIG. 1 shows the salient components of a wireless telecommunications system 100 in accordance with the prior art. The system 100 comprises: wireless terminal 101 and 110, cellular base stations 102-1, 102-2, and 102-3, Wi-Fi base stations 103-1 and 103-2, and wireless switching center 111, and location system 112 interconnected as shown. Wireless telecommunications system 100 provides wireless telecommunications service to all wireless terminals in its coverage areas, in well-known fashion. Location system 112 provides data indicating the geographic location of a mobile unit. Global Positioning System constellation 121 is also depicted in FIG. 1, but it is not part of wireless network 100.
There are a variety of reasons why a remote party might be interested in knowing the user's location. For example, the recipient of an E 9-1-1 emergency call from a wireless terminal might be interested in knowing the location of the wireless terminal so that emergency services vehicles can be dispatched to that location. Or, if the wireless terminal remains mobile, the emergency services may wish to track its location.
Despite the advantages of tracking and locating mobile units, there are users of wireless terminals who wish to avoid tracking. Sometimes these users wish to avoid tracking in aid of unlawful or dangerous activity. Such users may employ multiple cell phones, each having its own Subscriber Identity Module (SIM), Mobile Equipment Identifier, or International Mobile Station Equipment Identity, depending on the technology in use. Others have been known to discard and replace mobile phones on a very short-term basis. By doing so, these users in effect use multiple identifiers or aliases and may do so for nefarious reasons.
At times, an analyst may wish to understand whether mobiles are actually aliases of each other. This could arise where the mobiles are known to be active or where one mobile is a suspected replacement of another. In other cases, an analyst may wish to learn all the potential aliases of a known mobile either currently in use or discarded. Due to the nature of mobile telephone use, mobile unit identifiers can be considered user identifiers for tracking purposes. US Publication 2014/0038553, “Recognizing Unknown Actors Based on Wireless Behavior,” (the '553 Application) incorporated here in full by reference, discloses a system and method for analyzing telecommunication events to infer whether a user's mobile unit behavior substantially matches the behavior of another mobile unit.
In the illustrative method of the '553 Application, a data processing system generates a pattern of behavior based on events associated with a wireless terminal. A mobile's pattern of behavior comprises mobile events and location attributes measured over some period of time. The pattern of behavior is measured against another pattern of behavior associated with a different mobile to determine how closely the patterns compare. Depending on the measured similarity, the data processing system infers whether the mobiles may belong to the same user. Examples of events include call origination, call reception, SMS origination, SMS receipt, powering on, location detection, etc., as has been previously delineated.
Despite the disclosure of the '533 Application, there remains a need to identify where a target uses two mobiles over a period of time, and where a target replaces one mobile with another. There also remains a need to identify potential mobile aliases from a group of aliases where no single mobile may be a target.